期刊文献+

Y型微通道内双重乳液流动破裂机理 预览

Hydrodynamics of double emulsion passing through a microfuidic Y-junction
在线阅读 下载PDF
收藏 分享 导出
摘要 基于体积分数法建立了Y型微通道中双重乳液流动非稳态理论模型,数值模拟研究了Y型微通道内双重乳液破裂情况,详细分析了双重乳液流经Y型微通道时的流场信息以及双重乳液形变参数演化特性,定量地给出了双重乳液流动破裂的驱动以及阻碍作用,揭示了双重乳液破裂流型的内在机理.研究结果表明:流经Y型微通道时,双重乳液受上游压力驱动产生形变,形变过程中乳液两端界面张力差阻碍双重乳液形变破裂,两者正相关;隧道的出现将减缓双重乳液外液滴颈部收缩速率以及沿流向拉伸的速率,并减缓了内液滴沿流向拉伸的速率,其对于内液滴颈部收缩速率影响不大;隧道破裂和不破裂工况临界线可以采用幂律关系式l~*=βCa~b进行预测,隧道破裂和阻塞破裂工况临界线可以采用线性关系l~*=α描述;与单乳液运动相图相比,双重乳液运动相图各工况的分界线关系式系数α和β均相应增大. A scheme of passive breakup of generated droplet into two daughter droplets in a microfluidic Y-junction is characterized by the precisely controlling the droplet size distribution.Compared with the T-junction,the microfluidic Y-junction is very convenient for droplet breakup and successfully applied to double emulsion breakup.Therefore,it is of theoretical significance and engineering value for fully understanding the double emulsion breakup in a Y-junction.However,current research mainly focuses on the breakup of single phase droplet in the Y-junction.In addition,due to structural complexity,especially the existence of the inner droplet,more complicated hydrodynamics and interface topologies are involved in the double emulsion breakup in a Yjunction than the scenario of the common single phase droplet.For these reasons,an unsteady model of a double emulsion passing through microfluidic Y-junction is developed based on the volume of fluid method and numerically analyzed to investigate the dynamic behavior of double emulsion passing through a microfluidic Yjunction.The detailed hydrodynamic information about the breakup and non-breakup is presented,together with the quantitative evolutions of driving and resistance force as well as the droplet deformation characteristics,which reveals the hydrodynamics underlying the double emulsion breakup.The results indicate that the three flow regimes are observed when double emulsion passes through a microfluidic Y-junction:obstructed breakup,tunnel breakup and non-breakup;as the capillary number or initial length of the double emulsion decreases,the flow regime transforms from tunnel breakup to non-breakup;the upstream pressure and the Laplace pressure difference between the forefront and rear droplet interfaces,which exhibit a correspondence relationship,are regarded as the main driving force and the resistance to double emulsion breakup through a microfluidic Y-junction;the appearance of tunnels affects the double emulsion deformation,resulting in the slower squeezing spe
作者 俞炜 邓梓龙 吴苏晨 于程 王超 Yu Wei;Deng Zi-Long;Wu Su-Chen;Yu Cheng;Wang Chao(Key Laboratory of Energy Thermal Conversion and Control,Ministry of Education,School of Energy and Environment,Southeast University,Nanjing 210096,China;School of Hydraulic,Energy and Power Engineering,Yangzhou University,Yangzhou 225127,China)
出处 《物理学报》 SCIE EI CAS CSCD 北大核心 2019年第5期171-184,共14页 Acta Physica Sinica
基金 国家自然科学基金委员会-中国工程物理研究院NSAF联合基金(批准号:U1530260) 国家自然科学基金(批准号:51776037) 江苏省自然科学基金(批准号:BK20180405)资助的课题.
关键词 Y型微通道 双重乳液 破裂 体积分数法 Y-junction double emulsion breakup volume of fluid method
作者简介 通信作者:邓梓龙,E-mail:zldeng@seu.edu.cn
  • 相关文献
投稿分析

相关作者

内容加载中请稍等...

相关机构

内容加载中请稍等...

相关主题

内容加载中请稍等...

浏览历史

内容加载中请稍等...
;
使用帮助 返回顶部 意见反馈